Penn Herb Wellness Guide
N-Acetyl CysteineFind Products
Side Effects
One study reported that 19% of people taking NAC orally experienced nausea, vomiting, headache, dry mouth, dizziness, or abdominal pain.2 These symptoms have not been consistently reported by other researchers, however.
Although a great deal of research has shown that NAC has antioxidant activity, one small study found that daily amounts of 1.2 grams or more could lead to increased oxidative stress.3 Extremely large amounts of cysteine, the amino acid from which NAC is derived, may be toxic to nerve cells in rats.
NAC may increase urinary zinc excretion.4 Therefore, supplemental zinc and copper should be added when supplementing with NAC for extended periods.
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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.